


Take Your Vitamins!

by AhHHH (Plaideria)



Series: Klance Smut [3]
Category: Voltron: Legendary Defender
Genre: Anal Fingering, Anal Sex, Blow Jobs, Bottom Lance (Voltron), Come Swallowing, Creampie, Dirty Talk, Face-Fucking, Fluff and Smut, Galra Keith (Voltron), M/M, Mating Cycles/In Heat, Plot What Plot/Porn Without Plot, Top Keith (Voltron)
Language: English
Status: Completed
Published: 2018-02-24
Updated: 2018-02-24
Packaged: 2019-03-21 09:44:16
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,874
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13738224
Author URL: https://archiveofourown.org/users/Plaideria/pseuds/AhHHH
Summary: Keith starts to take vitamins that have nutrients meant specifically for Galra growth. However, the pills come with some side effects.





	Take Your Vitamins!

**Author's Note:**

> So this is a kind of sequel to my other work "Keith Doesn't Approve". This c. An be read on its own so don't worry about the other part if you'd rather not :3
> 
> This is a request from Ren!
> 
> "but would you maybe do a story where Keith (top) and Lance (bottom) officially become 'mates'? I think it's interesting how the galra see that as a more 'I'm in a relationship and taken' rather than just telling people that a person is not available."
> 
> O o f I'm sorry it took a bit ;w; I hope it isn't weird or anything and that you like it!
> 
> Also I wrote this on my phone so there may or may not be some mistakes. sorry in advance! ^^"

"There you go, my boy!" Coran stated cheerfully as he dropped a clear bottle of dark purple pills into Keith's hands. "Two of these a day should help you out."

Lance raised an eyebrow as Keith turned the bottle over in his hands. The three of them currently stood in the empty hallway leading to Keith and Lance's room. Lance looked around before shooting Coran a confused look. "Help him with what?" 

"Do you not remember?" Coran asked with his own look of confusion. "You both came to me for help with Galra... Mating. I told you I would explain when I could. And I can right now. If you're still interested that is?"

Lance made a small 'oh' sound as he remembered asking Coran the very question. 

* * *

 

_The days after Keith threatened Leouch, Lance was left alone. Leouch barely sent Lance a glance, even when they accidentally bumped into one another._

_Lance and Keith found themselves plagued with the whole bond thing Leouch had spoken of. What was it? It definitely had to be some Galra thing. So, they sought out Coran._

_"Coran, what's mating for a Galra?" Keith had asked when they bumped into Coran. If it was what they thought it was, this would be a very awkward exchange._

_Coran, who had been enjoying a nice platter of food good, sputtered and choked a little. "My apologies. May I hear that one more time?"_

Great,  _Lance thought with an internal sigh._ Now we're going to get  _the talk_ from Coran.

_"Mating," Keith restated and Lance gawked at his boyfriend who seemed unfazed. "Leouch mentioned it. What is it?"_

_Coran reached up and tapped his chin. He nodded after a few seconds. "I must request you both to wait a bit, if that's alright. I'll explain more when I can!" The Altean turned and retreated from the kitchen, continuing to eat his food good and seemingly muttering things to himself._

* * *

"Now," Coran gestured to the bottle of pills in Keith's hands. "Those pills are filled with nutrients essential to growing Galra.

"Now," Coran gestured to the bottle of pills in Keith's hands. "Those pills are filled with nutrients essential to growing Galra. Keith, since you grew up on Earth with limited access to these nutrients you haven't matured as all Galra do, including hybrids like yourself."

Keith looked up cautiously. "And what will happen if I start to take these?"

"I'm glad you asked, my boy! Galra are exceptionally strong and physically gifted and even hybrids become decently tall and muscular. You're a bit on the shorter side which is most likely a side effect of not having the correct nutrients," Coran stated, making had gestures as he spoke.

Lance looked at Keith, noting the slight height difference. Sure, Keith was a bit short and looked delicate, but all the same, Keith was strong. Lance had lost count the amount of times Keith had pinned him to the training deck, wall, and bed alike. "So, are these things just going to make him stronger? What does that have to do with what we asked about?"

"Patience!" Coran chided, wagging a finger in the air. "First what I want to say is, I very much doubt you'll receive any obvious physical Galra traits. Galra genes are recessive, most of the mixes you've seen look more like their counterpart than the Galra."

"Good," Keith said with a firm nod. Lance looked at his boyfriend with a raised eyebrow.

Lance wouldn't have a problem with Keith looking Galra. Keith would still be Keith. But, Lance could understand why Keith would worry about that sort of thing.

"Now, about the mating," Coran started slowly, looking as if he were carefully choosing his words. "I'm honored you boys have trusted me enough to ask me about such a topic."

Lance shifted a bit, feeling antsy at the serious tone Coran had donned. He felt an arm nudge his own before Keith's hand slipped into his own, their fingers intertwining almost perfectly. Lance let his gaze go to Keith's face, relaxing at the soft smile on Keith's face. They kept eye contact before looking back to Coran who stood patiently.

"Mating is a large commitment to the Galra. Galra are very open about their physical relationships, it's not uncommon for one of them to have multiple partners," Lance glanced at Keith. That would explain Leouch's actions. "But when two mate, they are solely loyal to each other. The process is where the pills come in." Coran said, pointing to the pills.

So the whole mating thing was basically dating it seemed like. Lance glanced to the pills in Keith's free hand before listening to Coran once more.

"When Galra mate another, they place a mark on them. This mark will stay there permanently," Coran tapped the lower part of his neck. "They're generally placed in this area right here, but can go anywhere."

"Does it hurt?" Lance asked carefully. He would be on the receiving end of this and having a bite permanently in his skin sounded like it would hurt.

Coran shook his head with a reassuring smile. "No need to worry, my boy! The saliva secreted by the Galra is filled with an aphrodisiac type of substance. If anything it will feel quite pleasurable. In fact, other fluids are filled with the same substance."

Aphrodisiac, pleasurable, other fluids - sirens blared in Lance's head. They _were_ getting the talk from Coran. Great. Lance had had his suspicions before, but knowing they were confirmed made embarrassment flare inside him.

"So aside from the increase in strength and most likely height," Coran continued, making hand gestures. "Keith, you're going to get urges to mate. After the pills go into effect you'll go into a type of mating cycle where your body will give off pheromones and you'll crave sexual intercourse for a few of your Earth days. Don't fret, though. It will come in waves, so you'll still be able to pilot your lion."

Lance blinked, trying to catch up and understand everything being said. Essentially: Keith would become taller and stronger, give Lance some weirdly pleasurable neck bite, and go through a heat cycle like some sort of dog. Lance snorted in amusement at the last bit, glancing at Keith who just looked to be thinking seriously.

"Okay," Keith said after a bit. "I'll start to take them. Thank you, Coran."

Coran placed a supportive hand on Keith's shoulder. "Anytime. And if you two need anything, just let me know." The Altean removed his hand and walked down the hall with a friendly wave.

"Well that eventful," Lance said, looking at the pills in Keith's free hand. "Are you really okay with starting to take those?"

Keith looked at the bottle, tossing it and catching it a few times. His face was twisted as he thought carefully. "Yeah, I'm fine with it. If anything it'll make me a better fighter."

Lance snorted and shook his head. That was just like Keith. "It's your decision, cariño."

So, Keith began to take the pills. Two a day, every single day during breakfast. No change was evident in the first three weeks. Keith was basically the same. Then, when the fourth week hit, Lance started noticing changes.

Keith was taller now. Standing at the same height as Lance. Lance was absolutely baffled by it, seeing it had barely been a month since he had started to take the pills. Keith was also getting better at fighting, able to fight on the training deck at higher levels for longer amounts of time.

And the stamina Keith held in the training deck overlapped into the bedroom. Something Lance didn't mind one bit.

As well as everything else, Keith was much more touchy and affectionate. Usually, Keith was more touchy behind closed doors, whether or not it was sexual. As of late, however, he had gotten touchy everywhere. Mealtime, mission briefings, alright after and before missions, movie nights, everything. Keith always seemed to latch himself to Lance, whether it was holding onto Lance's hand, wrapping an arm around his waist, pulling Lance into his lap in and outside of their bedroom, and had begun to nuzzle Lance's neck whenever a conversation Keith wasn't part of was going on. 

Lance wondered if this mating cycle would be coming soon. How long were the waves Coran of?

"Lance?"

Would that be when Keith finally would be able to bite him and have the mark stay there permanently? The couple had tested it out so few times, but it never stayed.

"Lance? Buddy?"

Lance felt his stomach do a flip of excitement, the thought letting his mind wander to places it currently shouldn't. 

"Lance!"

Hunk's voice brought Lance from his trance. The blue paladin jumped slightly and looked to where Hunk sat in his seat in the yellow lion. "We're back. What were you thinking about?"

Right. They had been sent on a mission to some alien planet to retrieve some sort of metal Coran had mentioned that Pidge was dying to try. That weird, nerdy gremlin. Lance still loved them like a little sibling, though. 

Though, Hunk and Lance had been gone for two days. Lance couldn't help that his thoughts kept going back to Keith.

"Keith," Lance replied truthfully, turning the box over in his hands. It was shiny and metal, Lance could see his reflection starting back at him. "Think he missed me?"

"Oh yeah," Hunk said with a chuckle as he stood from his seat and stretched. "You know how he feels about you."

"Good point, bud," Lance laughed as the two exited the yellow lion. When the reached the hangar floor, Pidge bounded up to them, their eyes sparkling in excitement. 

"Did you guys get it?" They asked hopefully, practically bouncing up and down.

Lance thrust the package into Pidge's hands with a grin. "You know it."

Pidge grinned as they stared at the box. "Thank you so much!"

Hunk laughed and ruffled their hair. "Don't mention it. It was fun meeting the Grolions anyways. They had great food."

"You should tell me about it while I'm working with this," Pidge nodded to the box. They paused, turning their gaze to Lance. Their face was blank before grinning. "Oh yeah, you should probably check up on your boyfriend."

That look wasn't good. Lance swallowed nervously. "I was already planning on it. Why are you mentioning it?"

Pidge shrugged nonchalantly, but still grinned. "No reason. I recommend you go as soon as possible, though."

Lance didn't like the sound of that, but still nodded. He traded a confused look with Hunk before exiting the hangar, heading to the room he shared with Keith. Lance didn't bump into anyone in the halls, so he was alone when he made it to the door to the bedroom Keith was probably already in.

Lance's fingers hovered over the button to open it. Was Keith upset with him? It wasn't his fault he had to leave, Allura had thought him and Hunk were the best paladins for this certain mission. Especially since it mainly consisted of social activities. 

Lance shook his head. Whatever it was, they could work through it. Lance opened the the door, ready to take a step into the room before pausing and gasping for a second, the scent of warm cinnamon invading his nose. Not only the scent of cinnamon, but the room _reeked_ of sex. It was dark and Lance was unable to see clearly. He stepped in, the door shutting behind him with a mechanical sound. 

"Keith?" Lance called out. No response. Lance opened his mouth, ready to call out once more before he was shoved against the door, an unusually warm body pressed up against his. 

"Lance," Keith's voice came, deep, laced with lust, and somewhat pained. "Where have you  _been_?" 

With the lights being off, Lance could barely make out Keith's face. Barely, but still somewhat. His face was flushed bright red, pupils blown wide so there was but a sliver of violet. He also appeared to be naked, if the bare shoulders and warm erection pressing into Lance's clothed stomach was anything to go by. 

"Mission, remember? Miss me much?" Lance teased, but blinked in surprise when Keith whined in an animalistic manner.

"So fucking much," Keith mumbled, crashing his lips onto Lance's. Lance gasped and before he knew it Keith's tongue was being shoved in his mouth. Lance moaned and relaxed against the door, finally realizing the cinnamon scent was emitting from Keith. 

Keith pulled away, leaning down to lick and bite at Lance's neck. Lance moaned at the sensation, heat pooling down and fueling his erection. Keith took note of this and moved away for a split second. Lance felt his jacket and shirt be removed quickly before Keith was on him again. Now bare, Lance could feel Keith's slightly sweaty and unbearably hot chest against his own, as well as Keith's cock weeping against his stomach.

Lance felt his pants and boxers being pushed down in a rush, and he kicked them away as well as kicked off his shoes and socks. 

"I can't see," Lance gasped as Keith pinched and flicked one of Lance's nipples. His erection strained painfully against his pants. "Let me turn the light on-"

"No!" Keith cried out quickly, pulling his hands away from Lance. Lance whined at the loss. "You can't turn them on!"

Lance looked at Keith, raising an eyebrow. "Why not?" 

 Even in the dim light, Lance knew Keith was avoiding his gaze even though his head was turned to Lance. "I... Changed."

That sparked Lance's interest. "Changed? How?"

Keith mumbled something inaudible. 

"Huh?" Lance inquired.

"My dick! My dick changed, okay?" Keith blurted it out in a rush of words. Lance looked down, trying to decipher what had changed.

"I'm sure it's not that bad, Keith," Lance said gently, desperately wanting to turn the lights on. 

"Easy for you to say," Keith sighed. Lance could hear him shifting around nervously. 

Lance chuckled softly. "Keith, you know I'm not going to laugh at you, right? We're in this together."

No response for a few seconds. Lance could feel Keith move a hand to press the light switch, turning it on and bathing the room in bright light. 

Lance winced at first screwing his eyes shut before adjusting and opening them. He looked eye level at Keith, who was avoiding his gaze with an embarrassed expression. Lance let his gaze travel down, past the chest and stomach to where Keith's dick stood up.

Lance inhaled, not even slightly ashamed at the rush of arousal he felt at the sight of Keith's dick.

It had changed alright. Keith was now packing an extra two inches, looking thicker than he had before. Not only that, but there was some sort of ribs on it as well, similar to dildos Lance had back home. 

"Don't just stare," Keith mumbled. Lance would gladly do more than just stare.

Lance dropped to his knees, taking the monstrous cock in his hands and gazing at it from up close now. Above him, Lance heard Keith inhale sharply. Lance didn't look up, instead focusing in the fluid gathering on the tip of Keith's cock. It was a purplish-white. Lance flicked his tongue out to give the tip a kitten lick, both males moaning from it. For Lance the taste was divine. It was sweet and tasted like Keith. Lance gladly wrapped his mouth around the tip, sucking gently. 

 Keith groaned deeply and Lance felt his hands grab onto his short hair. Lance moaned at the feeling of his hair being pulled as he swallowed a bit more of Keith's cock, wondering how much he would be able to take into his mouth. He swiped his tongue against the underside of Keith's cock, feeling the ridges and shuddering in anticipation. This was going to be inside him later. 

"Fuck, Lance, you look so good on your knees," Keith moaned out, voice shaky. "I want to fuck your mouth - please?" 

When Keith asked like that, who was Lance to deny him? Lance pulled off the erection and smiled up at Keith. "Go for it. You know I don't have a gag reflex," Lance said with a wink. 

Lance barely had anytime to prepare, his only warning being a growl, before Keith twisted in his hair and pulled him back onto Keith's cock. Lance groaned at the feeling of Keith hitting the back of his throat, more of that delicious fluid being fed to him. Keith continued to pull Lance until all of his length was sheathed in Lance's mouth. 

It was hot. Physically and metaphorically. Lance groan came out muffled as he looked up at Keith. 

Keith inhaled sharply, hips stuttering slightly and moving the hot length an inch out of Lance's mouth for a second before sliding back in.

Lance moaned at the sensation, placing his hands flat on the cold floor for stability. He gave a slight nod up at Keith, indicating he was ready to start. Keith returned the nod before the thrusts started. 

The hands in Lance's hair held his head in place as Keith thrust his hips, sliding his cock in and out of Lance's mouth. Lance could only moan as his throat was assaulted again and again, making his cock jump in interest. 

It was fast paced, not that Lance minded of course. He loved the rough treatment. Above him, Keith let out small, animalistic noises as his hips stuttered every now and then.

Though Lance liked this treatment, his jaw was beginning to ache from being held open this wide for so long. 

Keith's hips stuttered and he stuffed his length all the way into Lance's mouth. Lance moaned at the stretch, Keith pulsing in his mouth. Soon, that sweet fluid was flowing down Lance's throat and sucked at it greedily. The taste was still as intoxicating, and Lance found this mind growing hazy and lust filled with each swallow. Keith gave labored breaths and gasps until he finished, sliding his cock from Lance's mouth. 

Normally when one came, they would go soft or at least somewhat soft. Not in Keith's case. No, Keith sprung back up in all of his glory. 

Lance gawked at it. "How are you still this hard?" He asked, gazing at the weeping tip. 

Keith groaned in annoyance and lust. "I dont know. It's been like this since this morning."

Lance nodded in sympathy as he stood, holding Keith hands in his. He led the other male to their bed with a smile, flopping onto his stomach and digging their lube out from under their pillow. "That's fine, we can get through this."

Keith crawled onto the bed silently. He sat behind Lance and watched as the tan male popped open the lube bottle. 

"Do you want to prep me or should I?" Lance asked, looking over his shoulder. .

Keith gave a conflicted look, glancing between his hand and Lance's ass. "You do it. I want to watch," Keith decided with a firm nod. 

Lance chuckled as he rose onto his knees, giving Keith a nice view of his plump ass. Lance covered his fingers in a generous amount of lube and reaching behind him. He circled his rim with the tips, sending Keith a flirtatious look from over his shoulder. "You know, I got ahold of some lube on that planet. I fingered myself last night thinking of you. I'm probably still stretched," to prove his point, Lance easily slipped two fingers into his hole, gasping as the feeling. Behind him, Keith groaned. 

Lance threw the battle to Keith so he could lube himself up as he pumped the fingers in and out of himself, letting out soft gasps and moans. Two fingers quickly turned to three, which turned into four sliding in and out as if it were natural. 

The fingers left his hole with a wet noise, Lance shuddered at the loss as he looked at Keith who was watching with a lustful expression. Lance laughed, gaining Keith's attention. "I'm ready whenever you are, cariño."

Keith shot up in record time. Lance barely had time to register it before his face was being shoved into the mattress and the head of Keith's cock was pressing against his entrance. Lance's mouth opened and he gasped gently as the first inch pressed in. He whined when he realized Keith had stopped. 

Lance squirmed, ready to ask what was wrong when Keith slammed in the rest of the way, tearing a startled cry from the Lance's throat. The unexpected stretch filled Lance with pain and pleasure and he gasped as his entrance convulsed around Keith length. 

Keith gave him a few seconds to adjust before sliding out slowly and Lance moaned as he could thoroughly feel the ridges rubbing him in all the right places. Before he knew it, Keith was slamming back in with a brutal pace, similar to when he fucked Lance's mouth just a little while prior. 

Lance could only like there letting out cries of pleasure, keening, begging for more. His mind was clouded with lust and all he could focus on was Keith and how he needed Keith to fill him over and over again. 

Orgasm wasn't too far away, and Lance wiggled his arm so he could stroke himself. He gasped and panted into the bedsheets, hot breath heating up the previously cool sheets and drooling on them a bit. 

That familiar, delicious feeling of Keith's cock pulsing inside him is what brought Lance over the edge. Lance cried out as he came all over his hand and the sheets, thighs quivering and entrance fluttering around Keith's erection. Above him, Keith growled and his thrusts became more erratic before he pushed in all the way, painting Lance's insides with the strangely sweet substance that had made Lance's mind hazy. 

Keith leaned over Lance's back, still planted inside him and bit into where Lance's neck met shoulder. Lance gasped as it broke skin, expecting pain, but instead greeted with pleasure that had him groaning and going limp. 

Keith gave a hum of approval as he pulled away, licking the bite gently. Lance would have made some comment if he could form a straight sentence. Instead, all that came out was a garbled noise.

* * *

 

"Its  _really_ staying there," Lance cried out in disbelief. He stood in front of the mirror in their bathroom, staring at the purplish-blackish mark that Keith had given him. "That's insane!"

Keith laughed as he walked over, looking at the mark. "That's what Coran said would happen. Or did you forget?"

"I forgot a lot of things when you decided to jump me right when I walked in," Lance countered with a wiggle of his eyebrows. 

Keith huffed and rolled his eyes. Lance chuckled. 

Lance's returned his gaze to his reflection. "But my  _flawless skin,_ Keith," Lance whined. It bothers him slightly, being with blemish everywhere except for right there. Keith snickered. 

"I like it," Keith said fondly, wrapping his arms around Lance's waist and resting his head on Lance's shoulder. He stared into Lance reflection as he whispered into Lance's ear. "Let's everyone know you're mine."

**Author's Note:**

> Y E ah so that happened :3 let me know what you guys thought!


End file.
